Fireplace heat exchanger



FIG. 1 is a perspective view of a fireplace heat exchanger showing my new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a side elevational view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a front elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The conventional cord has been shown fragmentarily in FIGS. 1 and 2 for ease of illustration. 

The ornamental design for a fireplace heat exchanger, as shown and described. 